Pontiac Repair: 2004 grand prix operating temp, coolant temperature sensor, crank case

Question
Dear Todd,
I recently had a similar issue as another poster who asked you a question a few days ago. My car always ran at, or very close to the 1/4 mark on the temp gauge even after a full day of heavy driving. I had some work done on the gaskets and ever since my temp has been running over the halfway point. My check engine light came on and I of course paid Pontiac $100 for them to tell me my thermostat was sticking. I replaced it with the oe recommended 195F but the car still runs hotter than I am used to. Is there any way to get back to the lower temp I am used to? What are the downsides to switching to a non-recommended stat such as a 180F? Will it keep turning on my check engine light if I switch to 180F? Also, could the coolant temperature sensor be bad? I'm fed-up with unknowledgeable people and spending loads of money on this seemingly simple problem....please help! :-) thanks! MarcusZ

Answer
Hey Marcus:

Well first off you don't wnt a cooler t/stat then the 195 for a few reasons. Less heat in you live in a cold cliamte. Fuel economy will drop. You will build up more sludge in the engein because it will not be able to burn off the condensation in the crank case. What was the code that set that turned the light on? Is it temp related or something else? the temp sensor on that car is the same one for the engine computer and the gauge. If the sensor was bad you would have driveability issues when the engine is cold if that was bad, the engine computer sents the temp reading to the gauge. the gauge could be off... the onlay way for sure to tell would you need a scan tool to see what the engine temp is reading in the engine computer data stream and an infered temp gauge to measure the temp of the water leaving the enegeins and see how close the 2 readings are.. The Gauge is just an indicator it's not exact. I don't know why after a repair it would read higher... Good luck :)